In order to comply with various governmental regulations, cigarette companies regularly test cigarettes in an automatic smoking machine that typically smokes twenty cigarettes simultaneously. The cigarettes are supported in the smoking machine by Cambridge filter units, each of which consists of a disc-shaped body containing a filter pad and having tubular stems extending forwardly and rearwardly from its opposite sides. A cigarette to be tested is inserted into one of these stems. The other stem is connected to a controlled vacuum source which causes air to be periodically drawn through the cigarette and the Cambridge unit as the cigarette is smoked by the machine. The smoke passes through the filter pad of the unit, and so-called "FTC tar" and moisture are retained by the pad. The entire unit is removed from the smoking machine and weighed after the cigarette has been smoked to a preselected extent. This weight is then compared to the weight of the unit prior to use thereof, to determine the "FTC tar" content of the cigarette.
Weighing of the Cambridge units, both before and after use thereof in smoking machines, is customarily now accomplished by technicians who manually place each unit upon a top-loading balance, record its weight, and then remove the pad from the balance. During a typical day over 600 individual weighings may be made in this manner. The foregoing technique for determining and recording the weight of the Cambridge units is highly inefficient, monotonous, tedious and error-prone, as a consequence of which it is unsatisfactory from the viewpoint of cost, accuracy of results and personnel satisfaction.